Such connections are intended in particular for feeding pneumatic actuators with fluid, and they suffer, in common with all flow rate regulating means having a passage of variable cross-section placed between an adjustable screw needle and an orifice, from the drawback of requiring a large number of turns to be performed in order to move the needle between its extreme positions. The screw pitch is chosen to be small enough to ensure that satisfactory sensitivity is obtained when adjusting small flow rates. In addition, the axial stroke given to such screws is directly influenced by the cone angle of the needle, and it is frequently observed that in the fully open position, the threaded shank of said screw or the knurled knob terminating it project a long way from the body in which they are mounted, and this can give rise to various operating problems and can give rise to misadjustments. In many cases, a considerable amount of manipulation is required before a satisfactory adjustment is found.
If the pitch of the needle screw thread is chosen to be large enough to reduce the number of turns that need to be made, the position of the screw is not stable, and it is essential to associate it with special locking means.
The invention seeks to provide a pneumatic connection whose general structure is as described above, but which also includes elements for mitigating the above-mentioned drawbacks.